Innovate Motorsports DL-32 - Manual (Page 18)

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The inductive clamp measures the magnetic field created around a spark plug wire when spark
current flows. If a metallic shield covers the spark plug wire, the inductive clamp may not work
because the shield would short out the magnetic field. Like all inductive clamp rpm pickup
devices, some ignition systems like Capacitive Discharge Ignition (CDI) or multi-spark ignition
systems may not work properly with the inductive clamp pickup because the pulses created may
be too short in duration. Multi-spark systems confuse the ignition timing measurement because
the RPM converter cannot distinguish which ignition pulse belongs to which crank rotation. The
DL-32 will work only on the tach output of the ignition system in this case.
The inductive clamp must be clamped around ONE lead only. Clamping it (for example)
around all wires of a coil-on-plug pack does not allow it to work because the magnetic
fields of the wires most likely cancel each other out.
7.4.1 Inductive Clamp Usage
- Plug the inductive clamp's 3.5mm audio plug into the RPM socket of the DL-32.
- Clamp the Inductive Clamp on the spark plug wire of one cylinder so the wire is completely
surrounded by the clamp.
- Make sure the clamp is completely closed.
- Start the engine.
- Switch on the LM-1 unit.
The decimal point of the digit display of the DL-32 should light up steadily. This indicates when a
valid RPM signal is detected. If it does not light up, or lights up intermittently, reposition or reverse
the clamp (try clamping it upside down). If the decimal point out only occasionally, that is OK.
The RPM converter will still convert, though its output might be noisy. A noisy output has spikes
or lengthy flat areas in the data log. [Note: to work properly with the inductive clamp pickup the
DL-32 must be set up for the appropriate number of pulses per crank rotation.]
• For a 4 stroke engine without waste spark ignition, this would be 1 pulse per 2 crank
rotations. This is the factory setting.
• For a 4 stroke engine with waste spark ignition, or a 2 stroke engine, this would be 1 pulse
per crank rotation.
• For a rotary engine, this would be 1 pulse per rotation. This is the same as for a 1-cyl 2-
stroke motor.
Note: On any distributor-less ignition system you can alternately clamp the inductive
clamp around one of the power wires on the primary side of the ignition coil or coil-on-
plug module.
7.5 Using the RPM-Converter with pulsed RPM input (Tach) signals
- Unplug the inductive clamp from the DL-32 if connected.
- Connect the RPM signal to the CH1+ input screw terminal.
The decimal point of the digit display of the DL-32 should light up steadily. This indicates when a
valid rpm signal is detected. If it does not light up, check your connections.
DO NOT CONNECT A PULSED RPM SIGNAL TO THE INDUCTIVE CLAMP INPUT. THIS
MIGHT DAMAGE THE DL-32 OR LM-1. Again, this should just result in an error code, not
mechanical damage.